DBMS_OUTPUT.NEW_LINE is a procedure provided by Oracle’s DBMS_OUTPUT package, which is commonly used for debugging and displaying output from PL/SQL code blocks, procedures, and triggers. The DBMS_OUTPUT package provides a way for the PL/SQL programs to communicate with the outside world by enabling them to send output to a buffer that can be accessed by SQL*Plus or other tools capable of displaying DBMS_OUTPUT buffer contents.
The NEW_LINE procedure specifically is used to add a new line character to the current output buffer, effectively simulating the pressing of the “Enter” key in a text editor. This is particularly useful for formatting output in a readable manner, especially when generating reports or outputting multiple lines of text in a loop.
Syntax
The syntax for DBMS_OUTPUT.NEW_LINE is straightforward:
DBMS_OUTPUT.NEW_LINE;
This procedure does not take any arguments. When called, it simply appends a newline character to the current output buffer.
Usage Example
To use DBMS_OUTPUT.NEW_LINE in conjunction with other DBMS_OUTPUT procedures to format output, you might write a PL/SQL block like the following:
BEGIN
DBMS_OUTPUT.PUT_LINE('Hello, World!'); -- Output a string followed by a newline
DBMS_OUTPUT.NEW_LINE; -- Add another newline for separation
DBMS_OUTPUT.PUT_LINE('This is a new line.');
END;
In this example, the first call to DBMS_OUTPUT.PUT_LINE outputs “Hello, World!” followed by a newline. The call to DBMS_OUTPUT.NEW_LINE adds another newline to the output buffer, effectively creating a blank line. Finally, another call to DBMS_OUTPUT.PUT_LINE outputs “This is a new line.” on a new line.
Considerations
Buffer Size Limit: The DBMS_OUTPUT package has a buffer that can hold a limited amount of data. If the buffer size is exceeded, older data can be lost. You can manage the buffer size with the DBMS_OUTPUT.ENABLE procedure.
Client Support: Not all clients automatically display the output collected by DBMS_OUTPUT. For example, in SQL*Plus or SQL Developer, you must run the command SET SERVEROUTPUT ON to enable the display of DBMS_OUTPUT content.
Debugging Use: While DBMS_OUTPUT is handy for debugging or learning, it is not typically used for displaying output in production applications. For user-facing applications, consider other methods of communication or logging.
The DBMS_OUTPUT.NEW_LINE procedure is a simple yet effective tool for improving the readability of debug output or for any scenario where formatted output from PL/SQL code is necessary.